Stem cell deficiency is seen in many ocular diseases and can lead to blindness. The condition is associated with a wide variety of maladies including burns, contact lens wear, dry eye, topical medications, and ocular disease associated with immunologic disorders and can even be seen postoperatively. Treatment of stem cell depletion associated with these conditions has been complicated by the inability to assess the stem cell niche in-vivo. For example, ten million people are bilaterally blinded by conditions with corneal involvement and an additional two million cases of monocular corneal blindness arise each year from trauma. Stem cell therapy and transplantation offers the possibility of cure for many of them.
An instance of one of the stem cell niches is the Palisades of Vogt, a poorly understood structure in the corneal limbus that provides the microenvironment necessary for survival and function of the corneal epithelial stem cells. Considerable variability in the size, shape and specific location of the palisades complicates identification and harvesting of stem cells for transplantation. Indeed, there are changes in the palisades in the normal course of aging as well as during disease conditions. While in-vivo confocal microscopy can be used to identify the palisades, it requires direct contact with the eye, is time consuming and covers a very limited area with each scan.